Ecological factors
In ecology, Ecological factors are variables in the environment that impact on organisms and contribute to their characteristic modes of behavior. They are factors that affect dynamic change in a population or species in a given ecology or environment are usually divided into two groups: abiotic and biotic. Abiotic factors are geological, geographical, hydrological, and climatological parameters. A biotope is an environmentally uniform region characterized by a particular set of abiotic ecological factors. Specific abiotic factors include: * Water, which is at the same time an essential element to life and a milieu * Air, which provides oxygen, nitrogen, and carbon dioxide to living species and allows the dissemination of pollen and spores * Soil, at the same time a source of nutriment and physical support ** Soil pH, salinity, nitrogen and phosphorus content, ability to retain water, and density are all influential * Temperature, which should not exceed certain extremes, even if tolerance to heat is significant for some species * Light, which provides energy to the ecosystem through photosynthesis * Natural disasters can also be considered abiotic Biocenose, or community, is a group of populations of plants, animals, microorganisms. Each population is the result of procreations between individuals of the same species and cohabitation in a given place and for a given time. When a population consists of an insufficient number of individuals, that population is threatened with extinction; the extinction of a species can approach when all biocenoses composed of individuals of the species are in decline. In small populations, consanguinity (inbreeding) can result in reduced genetic diversity, which can further weaken the biocenose. Biotic ecological factors also influence biocenose viability; these factors are considered as either intraspecific or interspecific relations. * Intraspecific relations are those that are established between individuals of the same species, forming a population. They are relations of cooperation or competition, with division of the territory, and sometimes organization in hierarchical societies. lies in wait under its pit trap, built in dry dust under a building, awaiting unwary insects that fall in. Many pest insects are partly or wholly controlled by other insect predators.]] *'Interspecific relations'—interactions between different species—are numerous, and usually described according to their beneficial, detrimental, or neutral effect (for example, mutualism (relation ++) or competition (relation --). The most significant relation is the relation of predation (to eat or to be eaten), which leads to the essential concepts in ecology of food chains (for example, the grass is consumed by the herbivore, itself consumed by a carnivore, itself consumed by a carnivore of larger size). A high predator to prey ratio can have a negative influence on both the predator and prey biocenoses in that low availability of food and high death rate prior to sexual maturity can decrease (or prevent the increase of) populations of each, respectively. Selective hunting of species by humans that leads to population decline is one example of a high predator to prey ratio in action. Other interspecific relations include parasitism, infectious disease, and competition for limited resources, which can occur when two species share the same ecological niche. The existing interactions between the various living beings go along with a permanent mixing of mineral and organic substances, absorbed by organisms for their growth, their maintenance, and their reproduction, to be finally rejected as waste. These permanent recycling of the elements (in particular carbon, oxygen, and nitrogen) as well as the water are called biogeochemical cycles. They guarantee a durable stability of the biosphere (at least when unchecked human influence and extreme weather or geological phenomena are left aside). This self-regulation, supported by negative feedback controls, ensures the perenniality of the ecosystems. It is shown by the very stable concentrations of most elements of each compartment. This is referred to as homeostasis. The ecosystem also tends to evolve to a state of ideal balance, called the climax, which is reached after a succession of events (for example a pond can become a peat bog). See also * Behavioral ecology * Ecological psychology * Environmental effects * Geography * Pollution * Topography Category:Ecology Category:Variables